The present invention relates to chest drainage devices, and more particularly to such devices which include noise attenuating means. More particularly, the invention relates to such chest drainage devices used with vacuum, the devices comprising three sets of chambers: collection chamber, liquid seal chamber, and suction control (manometer or pressure regulation) chamber.
During operation of these devices, a gas bubbles through a body of liquid maintained in one of the chambers. For example, atmospheric air bubbles through a body of liquid provided in the suction control chamber to regulate the amount of vacuum applied to the collection chamber. The devices are useful in maintaining clear passages and cavities under operative and post operative conditions. Under such circumstances, the noise associated with the bubbling gas is frequently annoying.
Chest drainage devices generally of the type disclosed herein are known in the art. Applicant is aware of the following documents generally pertinent to chest drainage devices including muffling means:
U.S. Pat. No. 3,782,497 to Bidwell et al discloses a sound muffling device for an underwater (chest) drainage unit which includes a plug-like member which is inserted in the opening to the atmosphere from the manometer chamber. This member is provided with a tortuous passageway therethrough in order to muffle the sound emanating from the device by reason of the bubbling of gas through the water in the manometer (suction) chamber.
U.S. Pat. No. 4,258,824 to Kurtz et al discloses an apertured baffle plate in the large arm of the manometer chamber of an underwater drainage device. The baffle plate is provided with a plurality of fine holes therein, and serves to break up the air bubbles into small bubbles in order to effectively muffle the sounds emanating from the device during use.
U.S. Pat. No. 4,289,158 to Nehring discloses a chest drainage collection system which includes a means for attenuating noise in the suction control container. Column 11, line 61 through column 12, line 26 of the Nehring specification discusses this aspect of the invention. This system enables the user to choose whether or not to use the option of controlling suction quietly. Lines 11-15 of column 12 indicate that if quiet operation is desired, tube 126 (as referenced in FIGS. 16 and 17) is stoppered by a suitable cap or plug.
U.S. Pat. No. 4,439,189 to Sargeant et al discloses a chest drainage device which includes a vacuum control (suction) container. This chamber includes an inlet straw 92 extending from the upper portion of the container down to near the bottom. Water is placed in the vacuum control means to provide a specific head. When vacuum in the chest drainage device is sufficient to overcome the head pressure, air is sucked in through straw 92 to relieve the excess vacuum. A cap having slots is fixed to the end of the straw to break up the incoming air bubbles. The sound of these bubbles is psychologically bothersome to the patient and the cap helps to quiet the device. At the upper end of the straw, an adaptor tube is positioned to receive the straw. The adaptor tube is fixed into the bottom of a smaller container compartment. The container provides an easy pour access for filling the vacuum control through the straw. To prevent plugging of the vacuum control and to help eliminate the sound of air bubbles in the system, a loose-fitting cap 104 is positioned over the container. The cap is removed for the purpose of filling the vacuum control.
U.S. Pat. No. 4,439,190 to Protzmann et al discloses a chest drainage device in which the suction control (manometer) chamber 6 is, of course, normally subjected to a negative pressure, since it is connected to a source of vacumm. This manometer chamber includes a tube 70 which extends from the fill port 96 to the bottom of the manometer chamber. Because of the vacuum applied by the vacuum source, there can be a substantial amount of bubbling from this tube which can be disturbing and noisy. In accordance with the invention of Protzmann et al, means is provided for reducing the amount of bubbling in the suction chamber. This means includes a foot member 72 which is attached to the tube 70 in any convenient manner. The foot member is enlarged and at its terminal or toe end includes a plurality of relatively small openings 74 (FIG. 26). The foot is attached to the tube so that the air bubbles emanating from the foot through the openings hit the front wall of the device, and the bubbles will follow a circular path to minimize splashing within the chamber. This circular pattern also helps prevent fluid from entering the suction line.